Describe, in general terms, the steps involved in the automated synthesis of the DNA sequence GCT.

Step 1
Attachment of 5'-DMT-N-benzoyl-2'-deoxyaguanosine to the polymer support by a 3' ester linkage.
Step 2
Deprotection of the 5'-hydroxyl by cleavage of the DMT ether with dichloroacetic acid in CH₂CL₂.
Step 3
Phosphite formation between the free 5'-hydroxyl of the polymer-bound N-protected 2'-deoxyguanosine and the phosphoramidite protected 5'-DMT-2'-deoxycytidine in the presence of tetrazole followed by oxidation to the phosphate triester with I₂.
Step 4
Repeat step 2 to deprotect the 5'-hydroxyl of the polymer-GC.
Step 5
Repeat step 3 to form the phosphate triester between 5'-hydroxyl of 2'-deoxycytidine residue and phosphoramidite protected 5'-DMT-N-benzoyl-2'-deoxythymidine.
Step 6
Cleave all protecting groups from the heterocyclic bases from the phosphates, as well as cleave the ester bond holding the DNA to the silica by treatment with aqueous ammonia.

Brilliant